Spororrminone A and 2-epi-spororrminone A, two new chromones from an endolichenic fungus Sporormiella irregularis

Abstract

Two new chromones, spororrminone A (1, (S)-5-hydroxy-2-methyl-4-oxo-2-((S)-5-oxotetrahydrofuran-2-yl)chroman-7-carboxylic acid) and 2-epi-spororrminone A (2, (R)-5-hydroxy-2-methyl-4-oxo-2-((S)-5-oxotetrahydrofuran-2-yl)chroman-7-carboxylic acid), were isolated from an EtOAc extract of an endolichenic fungal strain Sporormiella irregularis (No. 71-11-4-1). The structures of these compounds were identified by spectroscopic analyses. The absolute configuration of 1 was established by single-crystal X-ray diffraction. Spororrminone A (1) and 2-epi-spororrminone A (2) represent the first examples of 2-(5-oxotetrahydrofuran-2-yl) chromones with 7-carboxylic group.

Graphical Abstract

Keywords:

• Chromones
• 2-(5-oxotetrahydrofuran-2-yl) chromones
• spororrminone A
• 2-epi-spororrminone A
• Sporormiella irregularis
• endolichenic fungus

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [Nos. 3171101305 and 81673315]; the Chang Jiang Scholars Program from the Ministry of Education of China (No. Hao Gao, 2017); the Guangdong Natural Science Funds for Distinguished Young Scholar [No. 2017A03036027]; the Guangdong Special Support Program [No. 2016TX03R280]; the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme [No. Hao Gao, 2014]; the Pearl River Nova Program of Guangzhou [No. 201610010021]; K. C. Wong Education Foundation [No. Hao Gao, 2016].